1. Field of the invention
The present invention relates to a hard film to be formed on the surface of a film-formed product such as a jig or a cutting tool, a plastic working die including the hard film formed therein, a plastic working method using a plastic working die including the hard film formed therein, and a target for a hard film which is for forming the hard film
2. Background Art
Conventionally, plastic working dies using a cemented carbide, a cermet, a high-speed tool steel, or the like as the base material, specifically, jigs such as dies for cold stamping, dies for punching, and forging dies, and cutting tools such as tips, drills, and end mills are each required to have excellent wear resistance and sliding characteristics. For this reason, a hard film is formed on each surface thereof.
For example, in JP-A-2002-371352, there is a description to the effect that a vanadium-based film including one layer or two or more layers of any of VN film, VCN film, and VC film is formed.
Whereas, for example, in JP-A-2008-207219, there is a description to the effect that a film of TiN—TiCN—TiC applicable to use for pressing is formed.
However, the carbide films which are the technologies described in JP-A-2002-371352 and JP-A-2008-207219 are each high in reactivity with an iron-based material, and is unfavorably insufficient in wear resistance particularly for forming of a high-strength steel sheet.